The flight of a golf ball is determined by many factors, but only three factors are typically controlled by the golfer. By impacting the ball with a golf club, the golfer controls the speed, the launch angle and the spin rate of the golf ball. The launch angle sets the initial trajectory of the golf ball's flight. The speed and spin of the ball give the ball lift which will define the ball's overall flight path along with the weight and drag of the golf ball. Where the ball stops after being struck by a golf club also depends greatly on the weather and the landing surface the ball contacts.
Many golfers have what is termed a “low swing speed.” This means that the club head speed at impact is relatively slow when compared to a professional golfer's. Typically, when driving a golf ball the average professional golf ball speed is approximately 234 ft/s (160 mph). A person having a low swing speed typically drives the ball at a speed less than 220 ft/s (150 mph). A person with a low swing speed has a low ball speed. Consequently, his or her ball does not fly very far because of the lack of speed and lift. A significant percentage of all golfers today use such low swing speeds and consequently produce drives of less than 210 yards.
Typically, lightweight golf balls are designed for low swing speed golfers. These lightweight golf balls usually are two-piece solid balls made with a single-solid core, encased by a hard cover material. The resiliency of the core can be increased so that the compression is high, which in addition to making the balls stiffer, increases the initial velocity and decrease the ball's spin rate. This maximizes the distance achieved by low swing speed players. However, these balls tend to have a hard feel and are difficult to control around the greens.
U.S. Pat. No. 5,807,192 to Yamagishi et al. discloses a solid golf ball with a lightweight of 40 g to 45 g (1.41 ounces to 1.59 ounces). This golf ball includes a solid core and cover. The core has a diameter of 38 mm to 40 mm (1.49 inches to 1.57 inches). This ball will offer less spin due to the smaller core diameter resulting in a less performance oriented ball.
U.S. patent application Publication No. US 2002/0045500 A1 to Fushihara discloses a light weight two-piece golf ball with a weight of 35.0 g to 41.0 g (1.23 ounces to 1.44 ounces), and preferably 38.0 g to 40.5 g (1.34 ounces to 1.42 ounces). The Fushihara publication states that when the weight of the golf ball is greater than 41.0 g, the shot feel is heavy and poor. The core has a diameter of 36.5 mm to 42.5 mm (1.44 inches to 1.67 inches), preferably 36.7 mm to 40.8 mm (1.44 inches to 1.60 inches). Since this ball is so light (e.g., less than 41.0 g), it will exhibit faster velocity. This ball, however, will be easily affected by the wind.
U.S. Pat. No. 5,863,264 to Yamagishi et al. discloses a two-piece solid golf ball with a lightweight of 41 g to 44.5 g (1.45 ounces to 1.57 ounces). The golf ball includes a solid core and cover. The core has a diameter of 37 mm to 41 mm (1.45 inches to 1.61 inches), especially 38 mm to 40 mm (1.50 inches to 1.57 inches). The Yamagishi et al. patent further discloses a thermoplastic resin cover on the core.
A need exists for a high performance golf ball designed for low swing speed players that strikes a better balance between spin rate and distance to provide a distance ball with more control around the greens.